From the Latin, "Gemma", meaning "a bud", gemstones have been buried with man ,used in jewelry and art, fought over, and used as currency since before recorded history. Below are some of the gems you may recognize, and some you may not. Click on their names or scroll down to them. To see a larger image, click on the photos.
Amethyst Azurite Beryl Diamond Emerald Fluorapatite Garnet Opal Quartz Sapphire Smithsonite Turquoise
Click here to see a gemstones chart
photo© Smithsonian Institution
Amethyst is really purple quartz. Amethyst usually occurs in stubby crystals that line the interior walls of rock cavities. By heating amethyst up to 500 degrees Celsius, amethyst can change colors to yellow, red, and green.
photo© Smithsonian Institution
Azurite is actually a blue copper compound.
photo© Smithsonian Institution
From the mineral family, Beryl contains aquamarines, emeralds, heliodors, and morganite. The gems color is caused by chemical impurities.
photo© Smithsonian InstitutionDiamonds are crystallized carbon, formed by the intense heat and pressure of ancient volcanoes. Diamond is the most popular gemstone, and is supposed to be the symbol of true love.
At Murfreesboro, Arkansas, diamonds occur in a pipe of peridotite. This mine in Arkansas is the only diamond mine in the United States. A 40.23-carat crystal was the largest diamond found there. The mine is now a tourist attraction.Click here to learn strange Diamond facts.
photo© Smithsonian InstitutionEmerald, the green beryl, is the most valuable gem, after ruby. The earliest emerald mines were in the Sikait-Zubara region in Egypt near the Red Sea.
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photo© Smithsonian InstitutionFluorapatite is a member of the Apatite group. It contains more fluorine than chlorine.
photo© Smithsonian InstitutionGarnet has a group of family members that are similar, but look different. Garnet can range from red to green, depending on the minerals present when the gem forms.
photo© Smithsonian InstitutionThe Opals with bright colors on a black or brown background are called black opals. There are a lot of varieties of opals. Some are white opals, black opals, water opals, and fire opals. White opals have light pastel shades on it, while black opals have dark-gray, black, and blue shades. Water opals are transparent with colorless bodies, and fire opals are orange-red to red color, which looks like fire.
The most important opal place in the United States is in Virgin Valley, Humboldt County, Nevada, where black opals replaces wood.
Quartz (Crystals)
photo© Jessica MariskanishThe word crystal comes from the Greek word, krystallos which means "clear ice." Crystals are the most common minerals to find. They're glassy, dull, and transparent, which means you can see through them. Quartz is a hard mineral that can scratch window glass, and can't be scratched by a pocket knife or a steel file.
Pure quartz is colorless, but can be white, black, yellow, red, green, blue, violet, or brown. Quartz can be different colors because sometimes nearby atoms get inside the forming quartz that can change colorless quartz into different colors. The atoms that do this are called impurities.
There is plenty of quartz found in Texas and Arkansas, where quartz can be amethyst, milky quartz, rose quartz, smoky quartz, and rock crystal.
Click here to learn strange Quartz facts.
photo© Smithsonian InstitutionSapphire is large and well colored. From Sri Lanka, it is part of the collection of the National Museum of Natural History.
photo© Smithsonian InstitutionSmithsonite, a zinc carbonate was first discovered by James Smithson, a wealthy Englishman.
photo© Smithsonian InstitutionThe United States is the largest producer of turquoise. It is found in Arizona, New Mexico, Colorado, California, and Nevada.
For thousands of years, Persia (now Iran) produced the best turquoise. The term "Persian Turquoise" describes all fine (very good quality) turquoise.
Used to make jewelry and artwork, turquoise has been admired by man to the point that any color like it is called by its name.Two other gems resemble turquoise, but are separate mineral species. One is variscite, and the other is faustite. They have both been mistaken for and marketed as turquoise.
